Dental instrument



L. L. BOSWORTH DENTAL INSTRUMENT oo s, 1936.

Filed June 28, 1955 LUTHER LAWRENCE BOSWORTH -INVENTOR ATTORN Y PatentedOct. 6, 1936 UNI TED STATES PATENT OFFIQE DENTAL INSTRUMENT LutherLawrence Bosworth, San Diego, Calif.

Application Junez-28, 1935, Serial .No. 28,907

6 Claims.

This invention relates to a dental ossisector, the primary use of whichis to remove .bon-y structure overlying impacted teeth preparatory toextracting them.

To the dental profession the problem of impacted teeth is intenselyinteresting and of great importance. Heretofore only three methods havebeen employed in the removal of such teeth; (1) the chisel-and mallet,(2) the surgical drills; and. (3) the hand pressure cutting instruments.

Progress in dental surgery depends 'as much upon improving theinstruments employed as upon improved technique. There :has long beenfelt a need for improving present instruments in .such a manner as tomake it possible to cut bone with less pressure, less exertion, and lesstraumatization of tissue. Also to shorten the time required foroperations thus lessening the shock to the patient.

By this invention an instrument is provided whereby an improved andradically different method of operating upon impacted teeth is .renderedpossible, but the use of the invention is by no means confined toimpacted teeth. Instruments constructed according to the principles ofthis invention are applicable anywhere in the mouth, and whenbadlycurved or exostosed roots are found the tooth can be removed intactafter these instruments have been used to remove the obstructingtissues. Among the objects attained and advantages securedby the use ofthe instrument furnished by this invention may be mentioned thefollowing: Local anaesthesia may be used for all types of impactions; asafer control of instruments is ensured; the operatorcan see the fieldof operation at all times; bony tissure can be more easily removed; verylittle pressure is required when cutting away the bony structure; lesscutting is necessary; ease of operation results with less shock to thepatient; there is less trauma and a more rapid recovery; and "there isafforded to the operator greater ease and dispatch in the removal ofimpacted teeth.

Other objects, advantages and features of invention may hereinafterappear.

Referring to the accompanying drawing, which illustrates what is atpresent deemed to be a preferred embodiment of the invention,

Fig. 1 is a perspective view of the complete instrument.

Fig. 2 is a transverse section, on an enlarged scale, thru theapplicator portion thereof, on line 2-2 of Fig. 1.

Fig. 3 is a vertical section of the applicator portion, the plane ofsection being indicated by situation within the mouth of 'a patien't,the root I of thetooth beingoperated upon and those of adjacent teethbeing shown in dotted lines, another of the instruments being similarlyshown in readiness to perform the second stage of "the operation.

Fig. 5 is a 'view like Fig. 4 except that other types of instruments,constructed according to the principles of the invention are illustrated"and positioned for difierent cutting operations.

Fig. 6 is a side elevation outlining diagrammatically the applicatorportions of a set of instruments differing in design but all constructedin accordance with the invention.

Referring in detail to the drawing, the applicator portion 5 of theinstrument designed as shown-in Figs. 1,2:and-8 is of a somewhatwedgesh'a-ped character and has, extending lengthwise of its face aplurality of longitudinal, angular cutting ridges or blades. Bypreference and as :shown, these cutters consist of a prominent central"cutter '6, and outer cutter I at each side and a cutter 8 at each sidebetween an outer-cutter 1 and the central tooth 6.

The applicator :portion 5 is joined by means of :an offset neck 11 to adiametrically reduced portion I2 of the tool shank l3,'th'ere preferablybeing a definite annular shoulder l4 between'the shank portions 12 and 13. A transversely extending handle 15 having a fluted central portion [6is secured to the outer end of the shank 1 3.

Describing more in detail the applicator or cutting portion '5 of theinstrument, said portion, as viewed in transverse section, is somewhatconvex and preferably smooth along its back side I1, and its oppositeside or face is of a serrated, generally convex shape, the side portionsbeing chamfered or flattened at l8. Owing to the downwardly taperingcharacter of the cutting portion '5, each of the five angular cuttingridges thereof, which operates as a knife upon the bone with a shearingaction, diminishes downwardly in its cross sectional extent. The centralcutting ridge 6 is shown as substantially right angled in cross section,the a greater or less degree of angularity could be used withoutdeparting from the spirit of the claimed invention. The cutter ridges Iand 8 at each side of the center each have their faces disposed to eachother at less than a right angle as viewed in cross section, and performtheir cutting or shearing action when the to is rocked as indicated bythe arrows above Fig. 2. That is to say, the right hand cutters l and 8cut when the tool is rocked towards the left, and the corresponding lefthand cutters act when the tool is rocked in the opposite direction.

Fig. 4 shows the operative relation of the instrument in relation to animpacted molar tooth 20 to remove the obstructing portion of the bonystructure at one side of the crown of the offending tooth to permit theproper application of an elevator thereto. In removing the bony tissueas stated the instrument is operated by a rocking movement during whichits cutting surface may be either directed away from or towardthe toothto be elevated, while its smooth back surface is always directed towardsthe adjacent tooth instrument used at the beginning of an excavatingoperation, and (1 shows the position of another instrument substitutedfor the first in order that this operation may be satisfactorilycompleted, thereby providing a clearance above and behind the impactedmolar, so that it can be raised and extracted.

Altho the invention is illustrate-d in the drawing in an operativerelation to impacted teeth, yet it is to be understood that it has awide range of use in other situations for cutting bone when bone surgeryis indicated.

In Fig. 6 is shown a representative set of instruments constructedaccording to the principles of the invention. These instruments arelettered, from left to right, a, b, c, d, e and a, the instruments a anda differing from each other only in that one is for right, and the otherfor left hand use. Figs. 4 and 5 illustrate the use of instruments a, b,d and e. The instrument shown in Figs. 1, 2 and 3 is of a stilldifferent design.

In Fig. 6 the letter 12 is applied to the applicator portion of eachinstrument to designate the toothed or cutting face thereof.

So long as the general shape and arrangement of the cutting or shearingelements remain within the scope of the appended claims, various detailsthereof may be changed, as skilled workmen may desire, without departingfrom the spirit of the invention.

I claim:

1. An instrument of the kind described having an applicator portionwhich tapers from one end to the other, and a shank joining the largerend of said applicator portion, there being a set of oppositely disposedinwardly directed converging cutting ridges occupying one side or faceof said applicator portion which extend lengthwise thereof andprogressively diminish in their cross sectional extent away from thatend of the applicator portion which is joined to the aforesaid shank,the face of said applicator portion which is occupied by said cuttingridges being of a generally convex character as viewed in cross section.

2. A tool of the kind described having an applicator portion withoutwardly convexed opposite faces and a set of converging cutter ridgesextending longitudinally of one of said faces, the cutter edges at eachside of the medial portion of said applicator portion being directedtoward the midwidth thereof.

3. A tool of the kind described having an applicator portion withconvexed opposite faces and a plurality, of angular cutter ridges orblades extending lengthwise and slantingly of one of said faces, therebeing a central cutting ridge which runs longitudinally of the axis ofthe tool and projects farther than the others, and the slanting cuttersat each side of said central cutter substantially converging to a pointand having their cutting edges directed towards said central cutter.

4. In an instrument of the kind described, an applicator portion havingtwo oppositely disposed faces each of a convex character, saidinstrument having a shank portion united to one end of said applicatorportion, that end of said applicator portion being the largest and saidapplicator portion tapering toward its opposite or outer end, and therebeing a set of correspondingly tapering bone cutting knives or ridgesextending lengthwise of one of said convex faces, said knives includinga relatively large central knife which shears when the tool is rockedtowards either side and cutting knives at each side thereof whosecutting edges are directed towards said central knife.

5. A tool of the kind described, said tool having an applicator orcutting portion comprising two oppositely disposed faces each of whichconverge toward .a common point, one of said faces constituting a frontface and the other constituting a rear face, each of said faces being ofa convex character with the rear face of less convexity than said frontface, said front face having a plurality of converging cutters at eachside of the medial portion of said' applicator which are directed towardthe mid-width of the tool.

6. In an instrument of the kind described, an applicator portion havingtwo oppositely disposed faces of diverse convexities, said instrumenthaving a shank portion united to one end .of said applicator portion,that end of said applicator portion being the largest and saidapplicator portion tapering towards its opposite end, and a plurality ofcorrespondingly tapering inwardly directed knives on one of said faces.

LUTHER LAWRENCE BOSWORTH.

